Flow evener



- Sept. 4, 1951 HORNBOSTEL FLOW EVENER Filed June 26, 1946 I N V EN TOR.[1 am Hot/V8057! BY Patented Sept. 4, 1951 FLOW EVENER.

Lloyd Hornbostel, Beloit, wilt, "Signor to scion Iron Works, Bcloit,Via, a corporation of Wisconsin Application June 26, 1946, Serial No.679,420

Claims. 1

This invention relates to a flow evener type of stock inlet for a papermaking machine. Specifically, the invention deals with a cross flowstock evener for a paper making machine stock inlet wherein cross flowvelocity of stock is converted into a uniform transverse or lateral exitfeed velocity for insuring uniform flow conditions and fiber depositionacross the entire width of the paper machine forming surface.

According to the illustrated embodiment of this invention, a stock inletdefines a closed stock chamber immediately above and to the rear of thebreast roll end of a Fourdrinier type paper making machine. Thedischarge outlet for the chamber i provided between an apron carried bythe bottom wall of the chamber and a slice carried by the front wall ofthe chamber. The

opening or gap between the apron and slice is in communication with theupper run of the wire equipped with a cross flow box mounted beneath theclosed chamber. Stock is fed into the opposite ends of this box on thefront and rear sides of the paper machine. The box has tapered conduitsdiminishing in size from their inlet ends. The top of the box has a slotor gap communicating with both conduits and a rectifier roll isrotatably mounted immediately under this gap to receive stock from theconduits and feed the same through the gap into the bottom ends of theinlet. The rectifier roll contains a plurality of spaced opposedradially extending or transverse disks providing battles. These bailiesdirect the flow of stock through the holes in the rectifier roll toconvert cross flow'velocity into exit velocity and prevent formation ofeddy currents or cross velocities in the chamber defined by the inlet orhead box. If desired this chamber can be pressured with air or othercompressedv gas to force feed of stock out of the outlet therebyspeeding up production and avoiding the necessity for high heads in theinlet.

It is then an object of this invention to provide a flow evener for astock inlet wherein a rectifier roll convert cross flow velocity intodesired exit velocity.

Another object of the invention is to provide a cross flow type flowevener for paper making machines wherein stock from oppositely flowingstreams is directed through a rectifier roll which converts the crossflow velocity into a lateral uniform velocity and conditions the fiberarrangement in the stock to produce a stock that can be immediately setup into a sheet without further treatment on the forming surface of thepaper machine.

A further object of the invention is to provide a cross flow type flowevener with tapered transversely extending stock conduits convergingfrom the inlet ends thereof and having a common outlet along the lengththereof together with a rectifier roll rotatably mounted in said commonoutlet to receive the stock therethrough before it reache the outlet.

A still further object of the invention is to provide a rectifier rollequipped cross flow stock evener for the inlet of a paper machine.

. Other and further objects of the invention will be apparent to thoseskilled in the art from the following detailed description of theannexed sheet of drawings which, by way of a preferred example only,illustrates one embodiment of the invention.

0n the drawings:

Figure 1 is a somewhat diagrammatic side elevational view with parts invertical cross section of a Fourdrinier type paper making machineequipped with a stock inlet having a flow evener of this invention.

Figure 2 is a horizontal cross sectional view, with parts in top plan,taken along the line II-II of Fig. 1.

Figure 3 is a diagrammatic plan view illustrating the operatingprinciple of the flow evener of this invention.

As shown on the drawings:

As shown in Fig. 1 the reference numeral it I designates generally atock inlet or head box for a l ourdrinier type paper making machineincluding a forming wire II and a breast roll I! having the forming wiretrained therearound. The box It has a bottom wall l3 about level withthe upper run of the forming wire II and extending rearwardly from thebreast roll l2. Vertical side walls It extend upwardly from the bottomwall IS. A back wall i5 is provided between the side walls ll. A frontwall It is provided between the side walls H at the front end of the boxoverlying the upper run of the forming wire at the top of the breastroll II. The top of thebox is closed by a top wall l1 which has anopening l'la. therein closed by a door ll. An air inlet tube or pipe I!is also connected to the top wall I! to introduce air or other gasunderpressure to the box. The box has an elongated sump portion 2| beneaththe bottom wall H at the rear wall It. This sump portion 2| extendsacross the full width of the box between the side walls I. A horizontalbaflle 2i is equipped with a flow evener 26. evener 26 is mounted underthe sump 29 and has .tending into the slot 21.

. adapted to be-pressured by means of a compressed gasintroduced'through the tube l9, re-

. ceiving stock around the baille 2| from the sump 26 and dischargingstock through the outlet 24 under the slice 23 onto the wire I I.

'In accordance with this invention the box In This flow a dischargeslot'or gap 21 along its top face communicating with thesump 29 acrossthe entire width oi the sump.

As shown in'Figs. 1 and 2 the fiow evener 26 is composed of a box havinga bottom wall 29, spaced opposed parallel side walls 29 parallel withthe side walls H of the box ill, a diagonally sloping rear wall 30 and afront wall 3| parallel with the rear wall 30, together with a fiat topwall 32 containing the gap or slot 21. The walls 30 and 3| extenddiagonally relative to the line of .the paper making machine to definetapered flow conduits 33. on each side of a partition wall 34. Thesetapered flow conduits 33 decrease in size along their length from inlets35 in the side walls 29. Feed pipe 36 supplies both inlets 35 at theopposite ends of the box 26 and stock from the inlets 35 fiowslongitudinally along the length of the tapered conduits 33 on each sideOf the partition wall 34.

As shown in Fig. 1 the partition wall 34 ter- 'minates in spacedrelation beneath the outlet slot 21.

In accordance with this invention a rectifier roll 31 isrotatably'mounted in the box 26 immediately above the partition wall 34in close running clearance relationship therewith and projecting intothe slot 21 into close running clearance relation with the top wall 32.The rectifier roll 31 as best shown in Fig. 2 is composed Of aperforated tube 36 having a plurality of radially extending disks 39 inspaced parallel relation therein. These disks 39 are welded to theinterior of the tube. The tube 38 has open ends and the edges 38a of thetube have relatively close running clearance relationship with the sidewalls 29 of the box. The outer disks 39 are spaced inwardly from theends of the tube an appreciable distance and carry axles 40 whichproject through bearings in the side walls 29.

One of the axles 40 has a pulley 4| thereon driven by a belt 42 frommotor 43. The rectifier roll 31 is thus rotatably mounted in the box 26,with its axis aligned with the partition wall 34 and with the medianline of the slot 21, in close -running clearance with the upper edge ofsaid partition 34 and with its upper periphery ex- Thus, the oppositelyflowing streams of stock entering the box 26 must flow entirely throughthe rectifier roll 31 and through the slot 21 into the closed chamber25.

The tube 38.is perforated around its entire .periphery and along itsentire length. These perforations are graduated in size to diminish incapacity inwardly from the edges 38a of the tube.

Thus relatively large apertures 44 are provided in the tube near theends thereof and these apertures graduate in size down to relativelysmall apertures 46 at the mid-point of the tube. The

end edges 38a of the tube contain semi-aperturesskin eil'ects on theflowing stock normally imparted by the stationary side walls 29 iscompensated for by the reduced capacity holes in the mid-section oi. thetube.

As shown in the flow diagram of Fig. 3 stock enters the inlets 36 andflows in opposite directions through the passageways 33 in the box.These passageways are of diminishing size to compensate for discharge ofstock through the rectifier roll along the length of the roll so thatthe identical flow velocity will be maintained along the entire lengthof each passageway. Stock thus flows in opposite transverse directionsrelative to the line of the paper making machine and across the entirewidth of the paper making machine. This cross flow of stock insuresuniform delivery across the width of the machine. The stock from thepassageways 33 flows through the apertures in the tube 38 of therectifier roll and is guided by the disks 39 which form bafiles. Thebaiiles change the direction of how of the stock from oppositely flowingcross streams to upwardly flowing streams free from cross velocity. Inother words the baflies deflect the flow of stock from a cross flow toan exit flow. The stock flows through the rectifier roll and through thegap or slot 21 into the sump 20, thence around the baffle 2| and intothe chamber 25. The stock is allowed to rise to a predetermined level inthe chamber for maintenance of a desired head and the stock is thendischarged uniformly out of the outlet 24 onto the forming wire forimmediate setting into a paper sheet. The head of stock in the chamber25 can be maintained under superatmospheric pressure if desired byintroducing compressed gas into the chamber through the tube l9.

From the above description it will be understood that this inventionprovides an inlet having a cross flow box equipped with a rectifier rollto receive stock therethrough from oppositely flowing transversestreams. The rectifier roll is equipped with internal baffles whichdeflect the cross flow streams and form a uniform upwardly flowingstream. Any inequalities of stock distribution in the cross flow streamsis rectified by the roll and the roll has perforations so graduated asto nullify friction eflects on stock flow imposed by the walls of stockconduits or the like.

It will, of course, be understood that various details of constructionmay be varied through a wide range without departing from the principlesof this invention, and it is, therefore, not the purpose to limit thepatent granted hereon otherwise than necessitated by the scope of theappended claims.

I claim as my invention:

1. In a flow evener for a paper making machine having a partition walland side walls defining a pair of stock flow conduits adapted to receive0ppositely flowing stock streams and to discharge through a commonrestricted outlet spaced from the partition wall, the improvements whichcomprise a rectifier roll having a radially perforated cylindrical tube,means journalling the tube for rotation in position interposed betweensaid partition wall and said outlet to extend along the length thereofand cooperating with said partition wall in close running relationtherewith to prevent discharge from either of said conduits exceptthrough said tube, andradial baffles extending across the interior ofsaid tube and axially spaced along the length thereof to channel stockflow therethrough, said roll serving to merge the oppositely flowingstock streams for concurrent unidirectional discharge through saidoutlet and said bailies eliminating cross-velocities and eddy current inthe merged stock streams flowing through said sleeve.

2. In a flow evener for a paper making machine having a partitionwalland side walls defining a pair of oppositely tapered conduitsextending across the entire width of the evener and adapted to receiveoppositely flowing stock streams for discharge through a commonrestricted outlet vertically aligned with and spaced from the partitionwall, the improvement which comprises a rectifier roll comprising acylindrical tube having radial apertures therethrough of increasing sizeaxially outwardly toward each end from the center thereof, meansjournalling said tube for rotation in position interposed between saidpartition wall and said outlet to extend along the length thereof andcooperating with the partition wall in close running relationshiptherewith to prevent discharge through either of the conduits exceptthrough said tube, and a plurality of radial baffles axially spacedalong the lengths of the tube, said roll serving to merge the oppositelyflowing stock streams for concurrent unidirectional discharge throughsaid outlet and said baifles serving to eliminate crossvelocities andeddy currents within the merged stock streams.

3. In a flow evener for a paper making machine having an open toppedflowbox, closure means for the top of the box defining a restricted centraloutlet, and an upstanding partition wall defining a pair of separateadjacent stock fiow conduits adapted to receive oppositely flowing stockstreams and to discharge upwardly through said restricted opening, saidpartition wall being verticaly aligned with said rectricted opening, theimprovement which comprises a rectifier roll interposed between saidpartition wall and said restricted outlet and having its axis invertical alignment therewith, said roll cooperating with said partitionwall in close running relation therewith and extending into saidrestricted outlet to prevent discharge from either of said conduitsexcept through said roll, said roll also having axially spaced radiallyextending bafiles in the interior thereof and serving to merge theoppositely flowing stock streams for concurrent upward unidirectionaldischarge through said outlet with said radial baiiles serving toeliminat cross-velocities and eddy currents in said merged streams.

t. A stock inlet box for a paper making machine comprising a head boxdefining an interior closed chamber having an outlet at the forwardbottom end thereof and an inlet sump at the rear bottom end thereof, aflow evener box heneath said sump defining an interior space inrestricted communication with said sump through a discharge slotextending along the entire width of the inlet, an upstanding partitionwall in said flow box space terminating in spaced relation beneath saiddischarge slot and dividing said flow box space into a pair of adjacentstock conduits. means for introducing oppositely flowing stock streamsinto said conduits for discharge through said restricted slot to saidsump, and a rectifier roll interposed between said partition wall andsaid discharge slot, said roll extending into close running relationwith said partition wall and into said slot to prevent discharge fromeither of said conduits through said slot except through said roll, saidroll serving to merge the oppositely flowing stock stream of saidconduits for concurrent unidirectional discharge upwardly through saiddischarge slot into said sump.

5. A stock inlet box for a paper making machine comprising a head boxdefining an interior closed chamber having an outlet at the forwardbottom end thereof and an inlet sump at the rear bottom end thereof, aflow evener box be neath said sump defining an interior space inrestricted communication with said sump through a discharge slotextending along the entire width of the inlet, an upstanding partitionwall in said flow box space terminating in spaced relation beneath saiddischarge slot and dividing said flow box space into a pair of adjacentoppositely tapered stock conduits, means for introducing oppositelyflowing stock streams into said conduits for discharge through saidrestricted slot to said sump, and a rectifier roll interposed betweensaid partition wall and said discharge slot, said roll extending intoclose running relation with said partition wall and into said slot toprevent discharge from either of said conduits through said slot exceptthrough said roll, said roll having interior radial bafiles extendingthereacross and serving to merge the oppositely flowing stock streams ofsaid conduits for concurrent unidi rectional discharge upwardly throughsaid discharge slot into said sump and said baflles eliminatingcross-velocities and eddy currents within said slot.

LLOYD HORNBOSTEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Helin Sept. 18, 1945

